This invention relates to soft tissue anchors for securing soft tissue to bone. More particularly, this invention relates to a soft tissue anchor for securing labral tissue to the glenoid rim adjacent a human shoulder joint.
Throughout the human body, soft tissues connect to bone for various physiological reasons such as providing anchorage for muscles, connecting bones to one another, and providing protective capsules around joints, among others. For example, the human shoulder joint provides for articulation between the glenoid fossa of the scapula and the head of the humerus. The joint is surrounded by muscles and tendons that hold the joint together. These tissues connect to the glenoid rim of the scapula and form a fibrocartilage band around the glenoid fossa known as the glenoid labrum. In addition to being an anchorage for soft tissues around the shoulder joint, the glenoid labrum also deepens the glenoid fossa to form a more stable socket for the humeral head to fit within.
Various shoulder injuries, such as dislocations, falls, and throwing injuries, can result in the separation of the glenoid labrum from the glenoid rim. Different names have been attached to these separation injuries based on the location of the separation. For example, in a superior labral anterior posterior (SLAP) lesion, the labrum becomes separated near the top of the glenoid rim between the 11 o'clock and 1 o'clock positions. In a Bankart lesion, the labrum becomes separated between the anterior and inferior aspects of the glenoid rim between the 3 o'clock and 6 o'clock positions. Injuries such as these typically result in pain and instability in the shoulder joint. Treatment involves reattaching the labral tissue to the glenoid rim.
Soft tissue anchors for securing tissue to bone are known in the prior art, including anchors for connecting labral tissue to bone. Such devices are sometimes called tacks because they often have the appearance of a common tack. That is, the devices often have a shaft with a transverse head, the shaft having some projecting ribs, barbs or threads to enable the tack to be secured in the bone such as the glenoid rim. Most prior art tacks are suitable for reattaching many types of soft tissue and utilize symmetrical circular heads situated on an axially aligned shaft. However, recently a tack has been introduced with a non-symmetrical head particularly suitable for labral tissue as shown in FIG. 1. This device is generally “L”-shaped. The head extends only to one side of the shaft, away from the glenoid fossa, and extends at an angle of less than 90° from the shaft.